Dynamo action of the turbulence which is highly anisotropic under the influence of Coriolis and Lorentz forces, is investigated. The turbulence is taken to be driven by a random body force which is nearly homogeneous, isotropic and mirror-symmetric. Both the rotation and the magnetic field cause the intensity of the turbulent motion parallel to the rotational axis (or the line of force) to become larger than that of the perpendicular components by a factor √2.
The mean electromotive force of the anisotropic turbulence is evaluated separately to isolate the effects of the rotation and the magnetic field. The locally homogeneous turbulence creates two kinds (α-, and β-type) of electromotive forces under the influence of the rotation. The α-type includes a term proportional to the mean field (α-effect), and the β-type a term proportional to Ω×
J (Ω is the rotation rate and
J the mean current density). It is found that in the highly rotating systems both α-effect and the Ω×
J term are effective for the dynamo action. The magnetic field results in only the effect of producing the magnetic helicity which can be retained in derivation of the α-effect for the isotropic turbulence.
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